Angelique Kerber

Isner, Azarenka advance at Miami Open

American John Isner upset second-seeded Marin Cilic of Croatia 7-6 (0), 6-3 on Tuesday to reach the Miami Open quarterfinals.

The 14th-seeded Isner, who reached the Miami Open semifinals in 2015, never faced a break point in the match. He made an impressive 73 percent of his first serves to take down Cilic.

"I was in a very good serving rhythm today," Isner said. "I felt that really from my opening serve, the whole match that I knew it was going to be a good serving day.

"When I serve like that, I'm certainly tough to beat," Isner added.

The key to Isner's victory in the match came when he won all seven points in the first-set...